can you tell me the formula for telling the time diffrence between 2 times
when the either time may appear after midnight, without the need for a 48hr
clock

time due - 23:00 time arrived - 01:00 (2 hours)
time due - 01:00 time arrived - 23:00 (blank) but using a 24 hr clock this
shows as 22 ours late when in fact is 2 hours early

thanks